Thursday, August 24, 2006

I suppose many of you have probably heard this by now and I haven't been saying much on it, but it looks like the debate on the status of Pluto is over for now. As of this morning Pluto is no longer a planet and our solar system only has eight planets.

Many astronomy blogs have been mentioning this debate for some time now but I've refrained from commenting for a number of reasons. The first one was that I was waiting for the dust to settle and the vote to be taken before I went out on a limb and made any definative statements.

The second, and perhaps more important, is that I really don't think it's important from a scientific standpoint.

In all fairness, terms like "planet" are just labels. Ultimately the label isn't important as the object itself. The only reason we use labels at all is because it's convenient to have a single word to quickly transmit the concepts without having to go into very specific details. But where we draw the boundary lines is the tricky part.

To illustrate this point, take the word "star" as example. I'm willing to bet that when you read that word, the first image that pops into mind is an concept of a nice round star similar to our sun. Such stars are happily going about their life due to fusion. However, when you think about it some more, there's a lot of things that don't really fit this image, but none the less, are called stars: white dwarves, neutron stars, etc...

That's why I can't really find myself being too concerned with the status of Pluto as "planet" or not. The entire concept of planet is so overarching that it's not really useful in a scientific sense. But, even if we got down to the nit picky sub groupings, it still doesn't matter to much what we call it, but really, what its properties are.

So scientifically, I don't really worry too much about the designation. Therefore, I can't really say I understand the public outcry. Scientists are the ones that need a quick classification scheme, thus we're the ones that need to worry about such designations. For the general public, there's no good reason I can fathom that they should really care in the least.

The only reason that I can figure out is that it stems from a sense of ethnocentrism, since Pluto was the only (former) planet discovered by an American, and we really want our own to have made such important contributions. But ethnocentrism is a lousy way to make a definition.

So there you have it; My personal opinion on the whole matter. In short, who cares?

I guess the problem is that most of us can't believe there wasn't a definition before this. Pluto fits our layman's definition - it goes around the sun and it has moons, what else could it be but a planet? - and we don't get why what it's made of or what size it is is so important. Mercury's tiny, other planets are made of gas or rock ... I think there's less ethnocentrism than you think, but maybe that's only true among the people I know.

Ridger: I agree that your suggestion is an excellent possibility, but it reveals a profound danger that I was considering touching on in my original post: namely that when we start letting the public do things by their (incorrect) definitions, we cause confusion that can be (and is frequently) exploited by pseudo-scientists.

This happens all the time with the dual definitions for "theory" which is about the only reason ID can garner any mistaken scientific legitimacy. While the term "planet" is far less important, the pseudo-scientists have already been flocking around news of this decisions in the form of astrologers. Check out Bad Astronomy's blog. Phil over there has already heard from them.

Originally, there were seven planets. Each of the days of the week are named after them. For example, there's Sunday, and Moonday. There is no Earthday. Well, there is, but it isn't a day of the week.

We all know that planets are round. But when you look out your window, it's flat everywhere. That's why the Earth isn't a planet. Moreover, since there are some 10,000 Earth crossing objects, clearly, the Earth hasn't cleared out it's orbital space. That's why the Earth isn't a planet.

It seems that some of your colleagues are not quite so indifferent about the change as you are. The lead scientist on Nasa's robotic mission to Pluto lambasted the ruling, calling it "embarrassing." He is of the opinion that the Pluto vote was "hijacked" in revolt. I'm with you: I fail to understand why people get so hung up on semantics, but I'm no scientist -- there could be some perfectly valid reason related to the integrity of astronomical truth to get hung up on semantics.

There are many reasons for people to care about this. For one, the IAU decision was made in a very surreptitious backroom deal on the last day of the conference. Only 424 out of 10,000 members voted, and no email voting was allowed. Most of those who voted against Pluto's planethood were not planetary scientists. The process by which a decision is made is just as important as the decision itself, and this process was seriously flawed. There are several other problems as well. Linguistically, saying a dwarf planet is not a planet at all makes no sense. The IAU's claim that the term is a "compound noun" rather than an adjective modifying a noun is ridiculous--they are concocting their own rules of grammar to fit their needs. The "clearing its orbit" requirement is vague and produces a double standard because Neptune does not clear its orbit of Pluto yet is still considered a planet. In all, this decision has had a largely negative impact on the general public, creating a greater discord between the public and the scientific community. I for one care a great deal and strongly feel this arbitrary and capricious decision must be overturned. Dr. Alan Stern, Principal Investigator of the New Horizons mission to Pluto, is convening a conference of 1,000 astronomers this summer to address this issue, and I look forward to their coming up with a more sensible definition of planet that includes both Pluto and Eris.

Laurel Cornfield saidLinguistically, saying a dwarf planet is not a planet at all makes no sense.

Yet, we already have the term "minor planet", which is not considered a planet.

Personally, I would've liked to see dwarf planet classified as a type of planet, and not worried if that made for hundreds of planets. The 8 big ones would be "major planets".

However, ultimately,

As our host said The entire concept of planet is so overarching that it's not really useful in a scientific sense.

I agree. It seems odd to classify, for example, Jupiter and Earth in a single category, despite their very different natures, but then classify large moons such as ours and the Galilean moons as something different, even though they resemble Mercury, Venus, Earth, and Mars far more than those objects resemble Jupiter, Saturn, Uranus, and Neptune!

There are many reasons for people to care about this. For one, the IAU decision was made in a very surreptitious backroom deal on the last day of the conference. Only 424 out of 10,000 members voted, and no email voting was allowed. Most of those who voted against Pluto's planethood were not planetary scientists. The process by which a decision is made is just as important as the decision itself, and this process was seriously flawed. There are several other problems as well. Linguistically, saying a dwarf planet is not a planet at all makes no sense. The IAU's claim that the term is a "compound noun" rather than an adjective modifying a noun is ridiculous--they are concocting their own rules of grammar to fit their needs. The "clearing its orbit" requirement is vague and produces a double standard because Neptune does not clear its orbit of Pluto yet is still considered a planet. In all, this decision has had a largely negative impact on the general public, creating a greater discord between the public and the scientific community. I for one care a great deal and strongly feel this arbitrary and capricious decision must be overturned. Dr. Alan Stern, Principal Investigator of the New Horizons mission to Pluto, is convening a conference of 1,000 astronomers this summer to address this issue, and I look forward to their coming up with a more sensible definition of planet that includes both Pluto and Eris.

Originally, there were seven planets. Each of the days of the week are named after them. For example, there's Sunday, and Moonday. There is no Earthday. Well, there is, but it isn't a day of the week.

We all know that planets are round. But when you look out your window, it's flat everywhere. That's why the Earth isn't a planet. Moreover, since there are some 10,000 Earth crossing objects, clearly, the Earth hasn't cleared out it's orbital space. That's why the Earth isn't a planet.